VLAN Trunking

Sep 27, 2013

VLAN trunking is also known as tagged VLAN and 802.1Q tagging.
The 802.1Q tagging enables a networking device to add information
to a frame at Layer 2 to identify the VLAN membership of the frame.
Tagging also enables network environments to have VLANs that span
multiple devices. A device that receives the packet reads the tag
and recognizes the VLAN to which the frame belongs.

When you configure tagging on bridged interfaces, the VLAN
configuration must be identical on both ports of the bridge.

Tagged VLANs are not supported on the management interfaces
(ports 0/1 and 0/2).

For example, if your WAN link uses VLAN 412, you declare VLAN 412 as a tagged VLAN in the NetScaler
instance, and bind it to both ports of the bridge (such as ports
10/1 and 10/2), as shown in the example below.

Figure 1. Tagged VLANs for VLAN trunking. VLAN 412 is tagged

VLANs can be declared in either of two ways:

From the System > Settings > Configure NSVLAN Settings dialog box. This method declares a VLAN whose broadcast traffic is isolated from other VLANS. This method is recommended for the management subnet. It requires a restart to take effect.

Note: This VLAN configuration method is neither synchronized nor propagated in high availability mode. Therefore, you must perform the configuration independently on each appliance of a high availability setup.

From the Create VLANs dialog box (reached from Network > VLANs > Add..). This method does not create an isolated broadcast domain, from traffic originating in the NetScaler instance until we bind the NetScaler IP addresses to the VLAN. Adding such a VLAN does not require a restart. This method is recommended for all VLANs except the management subnet.